1. Field of the Invention
The present invention relates to an optical and/or electronic device, and more particularly to an optical and/or electronic device based on a novel operating principle.
2. Background Art
Conventional typical semiconductor devices are designed to operate by using electrons or holes near band edges of their conduction band or valence bands. For example, a light emitting device using a compound semiconductor of GaAs, or the like, utilizes emission of light by pair annihilation of electrons at the bottom of the conduction band and holes at the bottom of the valence band. However, state densities at the bottom of the conduction band and the bottom of the valence band are small, and therefore, when laser oscillation is intended, for example, there are limited electrons and holes, and this is one of the factors that impose the upper limit to the quantum efficiency. Needless to say, its reason lies in that electrons are Fermi particles and act on the Pauli exclusion principle.
Recently, nanostructures like quantum wires and quantum dots were made by using heterojunctions of compound semiconductors, and their application to light emitting devices is under discussion. This is because state densities of sub-band edges made by such artificial structures can be increased effectively and the quantum efficiency upon emission of light can be increased.
However, all of such conventional nanostructures were based on periodical structures, and such increase of density of states was limited, accordingly.
It is therefore an object of the present invention to provide an optical and/or electronic device based on a novel operating principle, which releases the limit of the conventional nanostructures and brings about degeneracy of density of states fundamentally.
The present Inventors made active studies toward solution of the above-mentioned problem, and as a result, reached the conclusion that the problem involved in the conventional techniques would be solved by degeneracy of density of states as a result of confinement of electrons in a region having fractal self-similarity, and not a periodical structure like a super-lattice structure, and reached the present invention.
In order to attain the above-mentioned object, according to a first aspect of the invention, there is provided an optical and/or electronic device characterized in the use of degeneracy of density of states by confinement of electrons or holes in a region having a self-similarity.
In a typical example of the first aspect of the invention, degeneracy of density of states is used for electron transition that follows emission.
According to a second aspect of the invention, there is provided an optical and/or electronic device characterized in the use of degeneracy of density of states by application of a random magnetic field to a region having a self-similarity.
The optical and/or electronic device according to the first aspect of the invention having the above-summarized configuration can generate a lot of electrons or holes equal in energy by using degeneracy of density of states by confinement of electrons or holes in a region having self-similarity, and by using it, the device can be used in various modes such as realization of a light emitting device with a high efficiency.
The optical and/or electronic device according to the second aspect of the invention having the above-summarized configuration can generate an quantum chaos more intensive than conventional devices by applying a random magnetic field to a region having self-similarity, through this process, can realize higher degeneracy of density of states, and by using it, can realize an optical and/or electronic device with a high efficiency.